Cars registered after 1/4/2018 will see their first year rate move up by one band so the cost of this will be £300 in total for a car like a 335d, and in fact that just equalises the situation so a new 340i will pay the same VED as a 335d.

Cars registered before 1/4/2018 are unaffected, so there is zero impact on existing cars

What changed in November 2017 for new diesel cars?
In the Autumn 2017 budget the Chancellor announced an increase in the first year VED rate for new diesel cars first registered after 1 April 2018.

The emissions test that Euro 6 diesel cars have to pass before they're approved for sale includes a more demanding, on-road 'Real Driving Emissions (RDE)' test from September 2017. This test is set to become even more stringent from January 2020 when 'RDE step 2' comes into force.

That was part of the argument against it. An incentive for people to stay in their old diesels longer, which is surely totally against what they are trying to achieve?

The Budget treatment of diesel cars was politically-motivated, and that's not too surprising with a wafer-thin majority and 11 million odd diesel cars on UK roads.

It would take a very brave Chancellor to try and tax older diesel cars off the road - something that Corbyn and his merry band of populists would no doubt seize upon as a tax on the poor. I can picture the Daily Mirror featuring a nurse who is now unable to drive to the soup kitchen. They could have brought in a scrappage scheme for say 12+ year old petrol and diesel cars, but that would be expensive.

Hence the very modest change which applies to new diesels from April 2018 only.

That was part of the argument against it. An incentive for people to stay in their old diesels longer, which is surely totally against what they are trying to achieve?

Not sure many understand the latest tax move. The motor industry can't see how it gives any incentive to ditch older diesels.

Plus the automatic tax band adjustment for new diesels, "unless" the diesel complies with the latest interpretation of the official test. Which no new diesel can be tested against, as it is not yet in force.

The first new models are only recently starting to go through WLTC RDE Step 1, ready for the September 2018 deadline. RDE Step 2 is still future.

Well i for one am very very happy i did not jump on the band wagon like most a ditch my Diesel. Its the best car for the motorway miles that i do, simple. Deep down i bet a lot of you who jumped ship now regret it, especially with the running costs, allthough you would never admit it. Its difficult for a man to admit that they were wrong. well thats what the wife tells me!